Abu Huraira reported: The Messenger of Allah, peace and blessings be upon him, said, “Whoever fasts the month of Ramadan due to faith and seeking reward, then Allah will forgive all of his previous sins. Whoever stands in prayer during the Night of Decree due to faith and seeking reward, then Allah will forgive all of his previous sins.”

Source: Ṣaḥīḥ al-Bukhārī 1802, Ṣaḥīḥ Muslim 760

Grade: Muttafaqun Alayhi(authenticity agreed upon) according to Al-Bukhari and Muslim